Comparison of JC viremia and viruria in 1-years follow-up: 21 MS vs 18 CD patients. (A.) Comparing JC viremia follow up of MS vs CD patients, the viremia of CD patients during the follow-up is numerically higher than that observed in MS patients, although we did not find a statistically significant difference (p = 0.07). (B.) Comparing JC viruria follow up of MS patients treated with natalizumab vs CD patients treated with infliximab, we observed a persistent viruria both cohorts. However the JC viruria of patients treated with infliximab, was significantly higher than that of patients treated with natalizumab only at t1 (p = 0.01) and at t3 (p = 0.05). Moreover a significant difference between the JC viruria detected at t0 and at t3 in both cohorts was also reported. JCPyV load values are expressed as log10 genome equivalent (gEq)/mL. JCPyV load values of MS cohort and CD cohort are reported in table 1 and table 4, respectively. Comparisons were performed using non parametric Mann–Whitney U-test and p values <0.05 were considered statistically significant. t0: baseline values. t1, t2 and t3: 4, 8 and 12 months of therapy, respectively.